MONDAY, Feb. 4 (HealthDay News) -- With the height of flu season here, the U.S Food and Drug Administration warns consumers to avoid fraudulent products that claim to prevent, treat or cure the flu.

These products haven't been tested and are not approved by the FDA. They can be found online and in retail stores, and may be marketed as dietary supplements or conventional drugs, foods (such as herbal teas), nasal sprays and devices (such as air filters and light therapies), the agency said in a news release.

"As any health threat emerges, fraudulent products appear almost overnight. Right now, so-called 'alternatives' to the flu vaccine are big with scammers," Gary Coody, the FDA's national health fraud coordinator, said in the news release.

Mary Malarkey, director of the FDA's Office of Compliance and Biologics Quality, added: "These unproven products give consumers a false sense of security. There is no need to buy a product that claims to be an alternative to the vaccine. Flu vaccine is still available, and it's not too late to get vaccinated."

There are no legally marketed over-the-counter (OTC) drugs to prevent or cure the flu, but there are legal OTC products to reduce fever and to relieve flu-symptoms such as congestion and muscle ache, the FDA said.

There are two approved prescription drugs -- Tamiflu (oseltamivir) and Relenza (zanamivir) -- that help fight the flu virus and may shorten the time you're sick. These two drugs can also be used to help prevent the flu, the agency said.

The best way to prevent the flu is to get vaccinated every year. The U.S. Centers for Disease Control and Prevention recommends the flu vaccine for adults and children over 6 months of age.